Aspects of the invention are directed to turbines and, more particularly, to turbines with an interrupted purge flow.
Generally, cooling air is employed to purge and cool cavities defined between rotating and static stages of turbines, such as gas turbines. For a gas turbine, the cooling air is book kept as a cycle penalty against the overall efficiency of the gas turbine as this air bypasses the turbine and combustor so that no work can be extracted from it.
Typically, the flow of the cooling air is governed by a diaphragm installed between rotating turbine stages. As such, associated nozzles include a static platform and pieces having knife-like edges.